Isolation of metallic salts of cytotoxic clerodanes from medicinal plant Polyalthia longifolia var. pendula.

Isolation of sodium and potassium salt of kolavenic acid (1,2), as a mixture of (3:1) and sodium and potassium salt of 16 oxo-cleroda-3,13(14) E-dien-15-oic acid (3, 4) as a mixture of (1:1) are first time reported form reddish black ripe and green unripe berries of Polyalthia longifolia var. pendula respectively. Three known constituents obtained, were identified as cleroda-3, 13(14) E-dien-15-oic acid (kolavenic acid) (5), 16(R and S)-hydroxy cleroda-3,13 (14)Z-dien-15,16-olide (6) and 16 oxo-cleroda-3,13(14) E-dien-15-oic acid (7). Structures of all these compounds have been determined through spectral studies while metal analyses were carried out to confirm the structure of the salts. Compounds 3, 4 and 7 possess cytotoxic activity against lung (NCI-H460), oral (CAL-27) and normal mouse fibroblast (NCI-3T3) cancer cell lines. Diterpenoid (7), a bioprivileged, compound shows potent cytotoxic activity against oral cancer cell line (CAL-27) with IC50 11.3±0.6µg/mL in comparison with the standard 5-flourouracil (IC50 12.7±0.1µg/mL) and lungs cancer cell lines (NCI-H460) with IC50 5.3±0.2µg/mL as compared to the standard drug cisplatin (IC50 5.7±0.2µg/mL).

Cytotoxic cardiac glycosides from the fruit (pods) of Adenium obesum (Forssk.) Roem. & Schult.

Phytochemical investigation of methanolic extract of Adenium obesum led to the isolation of 42 (1-42) compounds belongs to cardiac glycosides, triterpenoids and steroids. The chemical structures of isolated compounds were elucidated by spectral techniques UV, IR, NMR and FAB MS. The cardiac glycosides were tested against three human cell lines, 3T3 (normal cells), HeLa (Human cervical cancer cell lines) and PC-3 (Human prostate cancer cell lines). The cardiac glycoside, honghelin (4), obeside B (5) and obeside C (6) showed significant effects against cell lines Hela, 3T3 and PC-3 compared to standard drug doxorubicin. Compounds 4, 5 and 6 exhibited very low IC50 (µM) against the PC3 human cell line. 4 and 6 also showed least IC50 against the HeLa human cell lines as compared to the standard drug doxorubicin whereas these three compounds showed effect on 3T3 cell line with high IC50 values compared to drug cycloheximide.